Canada's prime minister Justin Trudeau has personally welcomed the first of 25,000 Syrian refugees Canada hopes to resettle over the next three months.

Key points

Canada's prime minister greets first of 25,000 Syrian refugees to arrive in the country

163 Syrians arrived by plane in Toronto

Canada is hoping to resettle 10,000 Syrians by the end of the year

Unlike the United States, there has been little opposition to the resettlement program

Government and opposition MPs joined Mr Trudeau in greeting the refugees when they landed in Toronto.

"This is a wonderful night, where we get to show not just a planeload of new Canadians what Canada is all about, we get to show the world how to open our hearts and welcome in people who are fleeing extraordinarily difficult situations," the prime minister said.

Mr Trudeau's Liberal government scaled back the number of Syrian migrants it will accept by year end after the attacks in Paris sparked concern that the election promise to bring in 25,000 by December 31 would not allow enough time for security checks.

The plane carrying 163 Syrian refugees touched down in Toronto just before midnight on Thursday (local time) and will be followed by a second military airlift to Montreal on Saturday.

Mr Trudeau has said 10,000 will be resettled by the end of the year and a further 15,000 by the end of February.

As he met the military aircraft amid tight security at a special terminal, privately sponsored Syrian refugees were arriving on commercial flights at Toronto's main terminal, greeted by sponsors and ordinary Canadians who had come to the airport to welcome the much-anticipated newcomers.

"They are very tired, but they are happy and hopeful," said Soriya Dasir, a worker with Abraham Festival, a group that sponsored a single mother and three children who had been living in a camp in Jordan for two years, as she escorted them past waiting media.

Warm reception contrasts with US response

Toronto's airport authority urged Canadians not to come to the airport to greet the refugees or drop off donations, saying: "We're so proud that our community wants to help, but such a response would be very overwhelming for those arriving."

The request did not deter Shai Reef, 20, who held up a sign that read: "Welcome to Canada" in Arabic.

"I'm here to show my solidarity for and support of the Syrian people going through genocide in Syria," Mr Reef said.

"As Jews, we were also locked out, I know what it feels like."

Toronto's mayor tweeted a welcome, while the Toronto Star, the country's largest newspaper, covered its front page with a "Welcome to Canada" banner headline in English and Arabic, along with an article explaining Canadian weather, ice hockey and slang.

The reception in Canada contrasted sharply with that of the neighbouring United States, where fear of Syrian refugees following the deadly November 13 Paris attacks spurred opposition to allowing them entry.

With security concerns, immigration paperwork and the flight's late-night arrival, refugees on the military aircraft were to be put up at a nearby hotel for the night before meeting their sponsors and resettlement agencies on Friday.